/*

Holder - 2.2 - client side image placeholders
(c) 2012-2013 Ivan Malopinsky / http://imsky.co

Provided under the MIT License.
Commercial use requires attribution.

*/

var Holder = Holder || {};
(function (app, win) {

var preempted = false,
fallback = false,
canvas = document.createElement('canvas');
var dpr = 1, bsr = 1;
var resizable_images = [];

if (!canvas.getContext) {
        fallback = true;
} else {
        if (canvas.toDataURL("image/png")
                .indexOf("data:image/png") < 0) {
                //Android doesn't support data URI
                fallback = true;
        } else {
                var ctx = canvas.getContext("2d");
        }
}

if(!fallback){
    dpr = window.devicePixelRatio || 1,
    bsr = ctx.webkitBackingStorePixelRatio || ctx.mozBackingStorePixelRatio || ctx.msBackingStorePixelRatio || ctx.oBackingStorePixelRatio || ctx.backingStorePixelRatio || 1;
}

var ratio = dpr / bsr;

var settings = {
        domain: "holder.js",
        images: "img",
        bgnodes: ".holderjs",
        themes: {
                "gray": {
                        background: "#eee",
                        foreground: "#aaa",
                        size: 12
                },
                "social": {
                        background: "#3a5a97",
                        foreground: "#fff",
                        size: 12
                },
                "industrial": {
                        background: "#434A52",
                        foreground: "#C2F200",
                        size: 12
                },
                "sky": {
                        background: "#0D8FDB",
                        foreground: "#fff",
                        size: 12
                },
                "vine": {
                        background: "#39DBAC",
                        foreground: "#1E292C",
                        size: 12
                },
                "lava": {
                        background: "#F8591A",
                        foreground: "#1C2846",
                        size: 12
                }
        },
        stylesheet: ""
};
app.flags = {
        dimensions: {
                regex: /^(\d+)x(\d+)$/,
                output: function (val) {
                        var exec = this.regex.exec(val);
                        return {
                                width: +exec[1],
                                height: +exec[2]
                        }
                }
        },
        fluid: {
                regex: /^([0-9%]+)x([0-9%]+)$/,
                output: function (val) {
                        var exec = this.regex.exec(val);
                        return {
                                width: exec[1],
                                height: exec[2]
                        }
                }
        },
        colors: {
                regex: /#([0-9a-f]{3,})\:#([0-9a-f]{3,})/i,
                output: function (val) {
                        var exec = this.regex.exec(val);
                        return {
                                size: settings.themes.gray.size,
                                foreground: "#" + exec[2],
                                background: "#" + exec[1]
                        }
                }
        },
        text: {
                regex: /text\:(.*)/,
                output: function (val) {
                        return this.regex.exec(val)[1];
                }
        },
        font: {
                regex: /font\:(.*)/,
                output: function (val) {
                        return this.regex.exec(val)[1];
                }
        },
        auto: {
                regex: /^auto$/
        },
        textmode: {
                regex: /textmode\:(.*)/,
                output: function(val){
                        return this.regex.exec(val)[1];
                }
        }
}

//getElementsByClassName polyfill
document.getElementsByClassName||(document.getElementsByClassName=function(e){var t=document,n,r,i,s=[];if(t.querySelectorAll)return t.querySelectorAll("."+e);if(t.evaluate){r=".//*[contains(concat(' ', @class, ' '), ' "+e+" ')]",n=t.evaluate(r,t,null,0,null);while(i=n.iterateNext())s.push(i)}else{n=t.getElementsByTagName("*"),r=new RegExp("(^|\\s)"+e+"(\\s|$)");for(i=0;i<n.length;i++)r.test(n[i].className)&&s.push(n[i])}return s})

//getComputedStyle polyfill
window.getComputedStyle||(window.getComputedStyle=function(e){return this.el=e,this.getPropertyValue=function(t){var n=/(\-([a-z]){1})/g;return t=="float"&&(t="styleFloat"),n.test(t)&&(t=t.replace(n,function(){return arguments[2].toUpperCase()})),e.currentStyle[t]?e.currentStyle[t]:null},this})

//http://javascript.nwbox.com/ContentLoaded by Diego Perini with modifications
function contentLoaded(n,t){var l="complete",s="readystatechange",u=!1,h=u,c=!0,i=n.document,a=i.documentElement,e=i.addEventListener?"addEventListener":"attachEvent",v=i.addEventListener?"removeEventListener":"detachEvent",f=i.addEventListener?"":"on",r=function(e){(e.type!=s||i.readyState==l)&&((e.type=="load"?n:i)[v](f+e.type,r,u),!h&&(h=!0)&&t.call(n,null))},o=function(){try{a.doScroll("left")}catch(n){setTimeout(o,50);return}r("poll")};if(i.readyState==l)t.call(n,"lazy");else{if(i.createEventObject&&a.doScroll){try{c=!n.frameElement}catch(y){}c&&o()}i[e](f+"DOMContentLoaded",r,u),i[e](f+s,r,u),n[e](f+"load",r,u)}}

//https://gist.github.com/991057 by Jed Schmidt with modifications
function selector(a){
        a=a.match(/^(\W)?(.*)/);var b=document["getElement"+(a[1]?a[1]=="#"?"ById":"sByClassName":"sByTagName")](a[2]);
        var ret=[];        b!==null&&(b.length?ret=b:b.length===0?ret=b:ret=[b]);        return ret;
}

//shallow object property extend
function extend(a,b){
        var c={};
        for(var i in a){
                if(a.hasOwnProperty(i)){
                        c[i]=a[i];
                }
        }
        for(var i in b){
                if(b.hasOwnProperty(i)){
                        c[i]=b[i];
                }
        }
        return c
}

//hasOwnProperty polyfill
if (!Object.prototype.hasOwnProperty)
    /*jshint -W001, -W103 */
    Object.prototype.hasOwnProperty = function(prop) {
                var proto = this.__proto__ || this.constructor.prototype;
                return (prop in this) && (!(prop in proto) || proto[prop] !== this[prop]);
        }
    /*jshint +W001, +W103 */

function text_size(width, height, template) {
        height = parseInt(height, 10);
        width = parseInt(width, 10);
        var bigSide = Math.max(height, width)
        var smallSide = Math.min(height, width)
        var scale = 1 / 12;
        var newHeight = Math.min(smallSide * 0.75, 0.75 * bigSide * scale);
        return {
                height: Math.round(Math.max(template.size, newHeight))
        }
}

function draw(args) {
        var ctx = args.ctx;
        var dimensions = args.dimensions;
        var template = args.template;
        var ratio = args.ratio;
        var holder = args.holder;
        var literal = holder.textmode == "literal";
        var exact = holder.textmode == "exact";

        var ts = text_size(dimensions.width, dimensions.height, template);
        var text_height = ts.height;
        var width = dimensions.width * ratio,
                height = dimensions.height * ratio;
        var font = template.font ? template.font : "Arial,Helvetica,sans-serif";
        canvas.width = width;
        canvas.height = height;
        ctx.textAlign = "center";
        ctx.textBaseline = "middle";
        ctx.fillStyle = template.background;
        ctx.fillRect(0, 0, width, height);
        ctx.fillStyle = template.foreground;
        ctx.font = "bold " + text_height + "px " + font;
        var text = template.text ? template.text : (Math.floor(dimensions.width) + "x" + Math.floor(dimensions.height));
        if (literal) {
                var dimensions = holder.dimensions;
                text = dimensions.width + "x" + dimensions.height;
        }
        else if(exact && holder.exact_dimensions){
                var dimensions = holder.exact_dimensions;
                text = (Math.floor(dimensions.width) + "x" + Math.floor(dimensions.height));
        }
        var text_width = ctx.measureText(text).width;
        if (text_width / width >= 0.75) {
                text_height = Math.floor(text_height * 0.75 * (width / text_width));
        }
        //Resetting font size if necessary
        ctx.font = "bold " + (text_height * ratio) + "px " + font;
        ctx.fillText(text, (width / 2), (height / 2), width);
        return canvas.toDataURL("image/png");
}

function render(mode, el, holder, src) {
        
        var dimensions = holder.dimensions,
                theme = holder.theme,
                text = holder.text ? decodeURIComponent(holder.text) : holder.text;
        var dimensions_caption = dimensions.width + "x" + dimensions.height;
        theme = (text ? extend(theme, {
                text: text
        }) : theme);
        theme = (holder.font ? extend(theme, {
                font: holder.font
        }) : theme);
        el.setAttribute("data-src", src);
        holder.theme = theme;
        el.holder_data = holder;
        
        if (mode == "image") {
                el.setAttribute("alt", text ? text : theme.text ? theme.text + " [" + dimensions_caption + "]" : dimensions_caption);
                if (fallback || !holder.auto) {
                        el.style.width = dimensions.width + "px";
                        el.style.height = dimensions.height + "px";
                }
                if (fallback) {
                        el.style.backgroundColor = theme.background;
                } else {
                        el.setAttribute("src", draw({ctx: ctx, dimensions: dimensions, template: theme, ratio:ratio, holder: holder}));
                        
                        if(holder.textmode && holder.textmode == "exact"){
                                resizable_images.push(el);
                                resizable_update(el);
                        }
                        
                }
        } else if (mode == "background") {
                if (!fallback) {
                        el.style.backgroundImage = "url(" + draw({ctx:ctx, dimensions: dimensions, template: theme, ratio: ratio, holder: holder}) + ")";
                        el.style.backgroundSize = dimensions.width + "px " + dimensions.height + "px";
                }
        } else if (mode == "fluid") {
                el.setAttribute("alt", text ? text : theme.text ? theme.text + " [" + dimensions_caption + "]" : dimensions_caption);
                if (dimensions.height.slice(-1) == "%") {
                        el.style.height = dimensions.height
                } else if(holder.auto == null || !holder.auto){
                        el.style.height = dimensions.height + "px"
                }
                if (dimensions.width.slice(-1) == "%") {
                        el.style.width = dimensions.width
                } else if(holder.auto == null || !holder.auto){
                        el.style.width = dimensions.width + "px"
                }
                if (el.style.display == "inline" || el.style.display === "" || el.style.display == "none") {
                        el.style.display = "block";
                }
                
                set_initial_dimensions(el)
                
                if (fallback) {
                        el.style.backgroundColor = theme.background;
                } else {
                        resizable_images.push(el);
                        resizable_update(el);
                }
        }
}

function dimension_check(el, callback) {
        var dimensions = {
                height: el.clientHeight,
                width: el.clientWidth
        };
        if (!dimensions.height && !dimensions.width) {
                if (el.hasAttribute("data-holder-invisible")) {
                        throw new Error("Holder: placeholder is not visible");
                } else {
                        el.setAttribute("data-holder-invisible", true)
                        setTimeout(function () {
                                callback.call(this, el)
                        }, 1)
                        return null;
                }
        } else {
                el.removeAttribute("data-holder-invisible")
        }
        return dimensions;
}

function set_initial_dimensions(el){
        if(el.holder_data){
                var dimensions = dimension_check(el, set_initial_dimensions)
                if(dimensions){
                        var holder = el.holder_data;
                        holder.initial_dimensions = dimensions;
                        holder.fluid_data = {
                                fluid_height: holder.dimensions.height.slice(-1) == "%",
                                fluid_width: holder.dimensions.width.slice(-1) == "%",
                                mode: null
                        }
                        if(holder.fluid_data.fluid_width && !holder.fluid_data.fluid_height){
                                holder.fluid_data.mode = "width"
                                holder.fluid_data.ratio = holder.initial_dimensions.width / parseFloat(holder.dimensions.height)
                        }
                        else if(!holder.fluid_data.fluid_width && holder.fluid_data.fluid_height){
                                holder.fluid_data.mode = "height";
                                holder.fluid_data.ratio = parseFloat(holder.dimensions.width) / holder.initial_dimensions.height
                        }
                }
        }
}

function resizable_update(element) {
        var images;
        if (element.nodeType == null) {
                images = resizable_images;
        } else {
                images = [element]
        }
        for (var i in images) {
                if (!images.hasOwnProperty(i)) {
                        continue;
                }
                var el = images[i]
                if (el.holder_data) {
                        var holder = el.holder_data;
                        var dimensions = dimension_check(el, resizable_update)
                        if(dimensions){
                                if(holder.fluid){
                                        if(holder.auto){
                                                switch(holder.fluid_data.mode){
                                                        case "width":
                                                                dimensions.height = dimensions.width / holder.fluid_data.ratio;
                                                        break;
                                                        case "height":
                                                                dimensions.width = dimensions.height * holder.fluid_data.ratio;
                                                        break;
                                                }
                                        }
                                        el.setAttribute("src", draw({
                                                ctx: ctx,
                                                dimensions: dimensions,
                                                template: holder.theme,
                                                ratio: ratio,
                                                holder: holder
                                        }))
                                }
                                if(holder.textmode && holder.textmode == "exact"){
                                        holder.exact_dimensions = dimensions;
                                        el.setAttribute("src", draw({
                                                ctx: ctx,
                                                dimensions: holder.dimensions,
                                                template: holder.theme,
                                                ratio: ratio,
                                                holder: holder
                                        }))
                                }
                        }
                }
        }
}

function parse_flags(flags, options) {
        var ret = {
                theme: extend(settings.themes.gray, {})
        };
        var render = false;
        for (sl = flags.length, j = 0; j < sl; j++) {
                var flag = flags[j];
                if (app.flags.dimensions.match(flag)) {
                        render = true;
                        ret.dimensions = app.flags.dimensions.output(flag);
                } else if (app.flags.fluid.match(flag)) {
                        render = true;
                        ret.dimensions = app.flags.fluid.output(flag);
                        ret.fluid = true;
                } else if (app.flags.textmode.match(flag)) {
                        ret.textmode = app.flags.textmode.output(flag)
                } else if (app.flags.colors.match(flag)) {
                        ret.theme = app.flags.colors.output(flag);
                } else if (options.themes[flag]) {
                        //If a theme is specified, it will override custom colors
                        if(options.themes.hasOwnProperty(flag)){
                                ret.theme = extend(options.themes[flag], {});
                        }
                } else if (app.flags.font.match(flag)) {
                        ret.font = app.flags.font.output(flag);
                } else if (app.flags.auto.match(flag)) {
                        ret.auto = true;
                } else if (app.flags.text.match(flag)) {
                        ret.text = app.flags.text.output(flag);
                }
        }
        return render ? ret : false;
}

for (var flag in app.flags) {
        if (!app.flags.hasOwnProperty(flag)) continue;
        app.flags[flag].match = function (val) {
                return val.match(this.regex)
        }
}
app.add_theme = function (name, theme) {
        name != null && theme != null && (settings.themes[name] = theme);
        return app;
};
app.add_image = function (src, el) {
        var node = selector(el);
        if (node.length) {
                for (var i = 0, l = node.length; i < l; i++) {
                        var img = document.createElement("img")
                        img.setAttribute("data-src", src);
                        node[i].appendChild(img);
                }
        }
        return app;
};
app.run = function (o) {
        preempted = true;
        
        var options = extend(settings, o),
                images = [],
                imageNodes = [],
                bgnodes = [];
        if (typeof (options.images) == "string") {
                imageNodes = selector(options.images);
        } else if (window.NodeList && options.images instanceof window.NodeList) {
                imageNodes = options.images;
        } else if (window.Node && options.images instanceof window.Node) {
                imageNodes = [options.images];
        }
        
        if (typeof (options.bgnodes) == "string") {
                bgnodes = selector(options.bgnodes);
        } else if (window.NodeList && options.elements instanceof window.NodeList) {
                bgnodes = options.bgnodes;
        } else if (window.Node && options.bgnodes instanceof window.Node) {
                bgnodes = [options.bgnodes];
        }
        for (i = 0, l = imageNodes.length; i < l; i++) images.push(imageNodes[i]);
        var holdercss = document.getElementById("holderjs-style");
        if (!holdercss) {
                holdercss = document.createElement("style");
                holdercss.setAttribute("id", "holderjs-style");
                holdercss.type = "text/css";
                document.getElementsByTagName("head")[0].appendChild(holdercss);
        }
        if (!options.nocss) {
                if (holdercss.styleSheet) {
                        holdercss.styleSheet.cssText += options.stylesheet;
                } else {
                        holdercss.appendChild(document.createTextNode(options.stylesheet));
                }
        }
        var cssregex = new RegExp(options.domain + "\/(.*?)\"?\\)");
        for (var l = bgnodes.length, i = 0; i < l; i++) {
                var src = window.getComputedStyle(bgnodes[i], null)
                        .getPropertyValue("background-image");
                var flags = src.match(cssregex);
                var bgsrc = bgnodes[i].getAttribute("data-background-src");
                if (flags) {
                        var holder = parse_flags(flags[1].split("/"), options);
                        if (holder) {
                                render("background", bgnodes[i], holder, src);
                        }
                } else if (bgsrc != null) {
                        var holder = parse_flags(bgsrc.substr(bgsrc.lastIndexOf(options.domain) + options.domain.length + 1)
                                .split("/"), options);
                        if (holder) {
                                render("background", bgnodes[i], holder, src);
                        }
                }
        }
        for (l = images.length, i = 0; i < l; i++) {
                var attr_data_src, attr_src;
                attr_src = attr_data_src = src = null;
                try {
                        attr_src = images[i].getAttribute("src");
                        attr_datasrc = images[i].getAttribute("data-src");
                } catch (e) {}
                if (attr_datasrc == null && !! attr_src && attr_src.indexOf(options.domain) >= 0) {
                        src = attr_src;
                } else if ( !! attr_datasrc && attr_datasrc.indexOf(options.domain) >= 0) {
                        src = attr_datasrc;
                }
                if (src) {
                        var holder = parse_flags(src.substr(src.lastIndexOf(options.domain) + options.domain.length + 1)
                                .split("/"), options);
                        if (holder) {
                                if (holder.fluid) {
                                        render("fluid", images[i], holder, src)
                                } else {
                                        render("image", images[i], holder, src);
                                }
                        }
                }
        }
        return app;
};
contentLoaded(win, function () {
        if (window.addEventListener) {
                window.addEventListener("resize", resizable_update, false);
                window.addEventListener("orientationchange", resizable_update, false);
        } else {
                window.attachEvent("onresize", resizable_update)
        }
        preempted || app.run();
});
if (typeof define === "function" && define.amd) {
        define([], function () {
                return app;
        });
}

})(Holder, window);